diff options
Diffstat (limited to 'usr.sbin/cron/cron.c')
-rw-r--r-- | usr.sbin/cron/cron.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/usr.sbin/cron/cron.c b/usr.sbin/cron/cron.c new file mode 100644 index 00000000000..39ef36ac2c3 --- /dev/null +++ b/usr.sbin/cron/cron.c @@ -0,0 +1,301 @@ +/* Copyright 1988,1990,1993,1994 by Paul Vixie + * All rights reserved + * + * Distribute freely, except: don't remove my name from the source or + * documentation (don't take credit for my work), mark your changes (don't + * get me blamed for your possible bugs), don't alter or remove this + * notice. May be sold if buildable source is provided to buyer. No + * warrantee of any kind, express or implied, is included with this + * software; use at your own risk, responsibility for damages (if any) to + * anyone resulting from the use of this software rests entirely with the + * user. + * + * Send bug reports, bug fixes, enhancements, requests, flames, etc., and + * I'll try to keep a version up to date. I can be reached as follows: + * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul + */ + +#if !defined(lint) && !defined(LINT) +static char rcsid[] = "$Id: cron.c,v 1.1 1995/10/18 08:47:30 deraadt Exp $"; +#endif + + +#define MAIN_PROGRAM + + +#include "cron.h" +#include <sys/signal.h> +#if SYS_TIME_H +# include <sys/time.h> +#else +# include <time.h> +#endif + + +static void usage __P((void)), + run_reboot_jobs __P((cron_db *)), + cron_tick __P((cron_db *)), + cron_sync __P((void)), + cron_sleep __P((void)), +#ifdef USE_SIGCHLD + sigchld_handler __P((int)), +#endif + sighup_handler __P((int)), + parse_args __P((int c, char *v[])); + + +static void +usage() { + fprintf(stderr, "usage: %s [-x debugflag[,...]]\n", ProgramName); + exit(ERROR_EXIT); +} + + +int +main(argc, argv) + int argc; + char *argv[]; +{ + cron_db database; + + ProgramName = argv[0]; + +#if defined(BSD) + setlinebuf(stdout); + setlinebuf(stderr); +#endif + + parse_args(argc, argv); + +#ifdef USE_SIGCHLD + (void) signal(SIGCHLD, sigchld_handler); +#else + (void) signal(SIGCLD, SIG_IGN); +#endif + (void) signal(SIGHUP, sighup_handler); + + acquire_daemonlock(0); + set_cron_uid(); + set_cron_cwd(); + +#if defined(POSIX) + setenv("PATH", _PATH_DEFPATH, 1); +#endif + + /* if there are no debug flags turned on, fork as a daemon should. + */ +# if DEBUGGING + if (DebugFlags) { +# else + if (0) { +# endif + (void) fprintf(stderr, "[%d] cron started\n", getpid()); + } else { + switch (fork()) { + case -1: + log_it("CRON",getpid(),"DEATH","can't fork"); + exit(0); + break; + case 0: + /* child process */ + log_it("CRON",getpid(),"STARTUP","fork ok"); + (void) setsid(); + break; + default: + /* parent process should just die */ + _exit(0); + } + } + + acquire_daemonlock(0); + database.head = NULL; + database.tail = NULL; + database.mtime = (time_t) 0; + load_database(&database); + run_reboot_jobs(&database); + cron_sync(); + while (TRUE) { +# if DEBUGGING + if (!(DebugFlags & DTEST)) +# endif /*DEBUGGING*/ + cron_sleep(); + + load_database(&database); + + /* do this iteration + */ + cron_tick(&database); + + /* sleep 1 minute + */ + TargetTime += 60; + } +} + + +static void +run_reboot_jobs(db) + cron_db *db; +{ + register user *u; + register entry *e; + + for (u = db->head; u != NULL; u = u->next) { + for (e = u->crontab; e != NULL; e = e->next) { + if (e->flags & WHEN_REBOOT) { + job_add(e, u); + } + } + } + (void) job_runqueue(); +} + + +static void +cron_tick(db) + cron_db *db; +{ + register struct tm *tm = localtime(&TargetTime); + register int minute, hour, dom, month, dow; + register user *u; + register entry *e; + + /* make 0-based values out of these so we can use them as indicies + */ + minute = tm->tm_min -FIRST_MINUTE; + hour = tm->tm_hour -FIRST_HOUR; + dom = tm->tm_mday -FIRST_DOM; + month = tm->tm_mon +1 /* 0..11 -> 1..12 */ -FIRST_MONTH; + dow = tm->tm_wday -FIRST_DOW; + + Debug(DSCH, ("[%d] tick(%d,%d,%d,%d,%d)\n", + getpid(), minute, hour, dom, month, dow)) + + /* the dom/dow situation is odd. '* * 1,15 * Sun' will run on the + * first and fifteenth AND every Sunday; '* * * * Sun' will run *only* + * on Sundays; '* * 1,15 * *' will run *only* the 1st and 15th. this + * is why we keep 'e->dow_star' and 'e->dom_star'. yes, it's bizarre. + * like many bizarre things, it's the standard. + */ + for (u = db->head; u != NULL; u = u->next) { + for (e = u->crontab; e != NULL; e = e->next) { + Debug(DSCH|DEXT, ("user [%s:%d:%d:...] cmd=\"%s\"\n", + env_get("LOGNAME", e->envp), + e->uid, e->gid, e->cmd)) + if (bit_test(e->minute, minute) + && bit_test(e->hour, hour) + && bit_test(e->month, month) + && ( ((e->flags & DOM_STAR) || (e->flags & DOW_STAR)) + ? (bit_test(e->dow,dow) && bit_test(e->dom,dom)) + : (bit_test(e->dow,dow) || bit_test(e->dom,dom)) + ) + ) { + job_add(e, u); + } + } + } +} + + +/* the task here is to figure out how long it's going to be until :00 of the + * following minute and initialize TargetTime to this value. TargetTime + * will subsequently slide 60 seconds at a time, with correction applied + * implicitly in cron_sleep(). it would be nice to let cron execute in + * the "current minute" before going to sleep, but by restarting cron you + * could then get it to execute a given minute's jobs more than once. + * instead we have the chance of missing a minute's jobs completely, but + * that's something sysadmin's know to expect what with crashing computers.. + */ +static void +cron_sync() { + register struct tm *tm; + + TargetTime = time((time_t*)0); + tm = localtime(&TargetTime); + TargetTime += (60 - tm->tm_sec); +} + + +static void +cron_sleep() { + register int seconds_to_wait; + + do { + seconds_to_wait = (int) (TargetTime - time((time_t*)0)); + Debug(DSCH, ("[%d] TargetTime=%ld, sec-to-wait=%d\n", + getpid(), TargetTime, seconds_to_wait)) + + /* if we intend to sleep, this means that it's finally + * time to empty the job queue (execute it). + * + * if we run any jobs, we'll probably screw up our timing, + * so go recompute. + * + * note that we depend here on the left-to-right nature + * of &&, and the short-circuiting. + */ + } while (seconds_to_wait > 0 && job_runqueue()); + + while (seconds_to_wait > 0) { + Debug(DSCH, ("[%d] sleeping for %d seconds\n", + getpid(), seconds_to_wait)) + seconds_to_wait = (int) sleep((unsigned int) seconds_to_wait); + } +} + + +#ifdef USE_SIGCHLD +static void +sigchld_handler(x) { + WAIT_T waiter; + PID_T pid; + + for (;;) { +#ifdef POSIX + pid = waitpid(-1, &waiter, WNOHANG); +#else + pid = wait3(&waiter, WNOHANG, (struct rusage *)0); +#endif + switch (pid) { + case -1: + Debug(DPROC, + ("[%d] sigchld...no children\n", getpid())) + return; + case 0: + Debug(DPROC, + ("[%d] sigchld...no dead kids\n", getpid())) + return; + default: + Debug(DPROC, + ("[%d] sigchld...pid #%d died, stat=%d\n", + getpid(), pid, WEXITSTATUS(waiter))) + } + } +} +#endif /*USE_SIGCHLD*/ + + +static void +sighup_handler(x) { + log_close(); +} + + +static void +parse_args(argc, argv) + int argc; + char *argv[]; +{ + int argch; + + while (EOF != (argch = getopt(argc, argv, "x:"))) { + switch (argch) { + default: + usage(); + case 'x': + if (!set_debug_flags(optarg)) + usage(); + break; + } + } +} |